<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        * {
            margin: 0px;
            padding: 0px;
        }
        .container {
            display: flex;
        }
        .box1 {
            position: relative;
            width: 300px;
            height: 300px;
            background-color: blanchedalmond;
            border: 1px solid red;
            margin: 10px;
        }
        .box1 .task {
            width: 60px;
            height: 60px;
            background-color: chartreuse;
            position: absolute;
            top: 0px;
            left: 0px;
        }
        .box2 {
            position: relative;
            width: 600px;
            height: 600px;
            background-color: rgb(15, 153, 172);
            border: 1px solid rgb(10, 10, 10);
            margin: 10px;
        }
        .mask {
            position: absolute;
            width: 300px;
            height: 300px;
            background-color: blanchedalmond;
            top: 0px;
            left: 0px;
        }
    </style>
</head>
<body>
    <div class="container">
        <section class="box1">
            <div class="task">

            </div>
        </section>
        <section class="box2">
            <div class="mask">

            </div>
        </section>
        <script>
            
        </script>
    </div>
</body>
</html>